Furn ce arch



Sepia. 1'1, 1928. 1,683,963

c. DUQUENNE FURNACE ARCH Filed April 14, 1924 2 Sheets-Sheet 1 Sept. 11, 1928.

' C. DUQUENNE FURNACE ARCH Filed April 14, 1924 2 Sheets-Sheet 2 Patented Sept. 11,

' CAIILLE DUQ'U'ENNE, PARIS, FRANCE.

II'UBNnCE ARCH.

Application illecl April 14, 1924, Serial I'm-706,548, and in Irance April, 87 1988.

My invention has for its object'the construction of flat walls which may have a large surface and may occupy a horizontal or slightly inclined position said walls being 6 adapted to withstand high temperatures at their lower parts whereby they may be em-.

ployed as roofs or arches for boiler furnaces or the like, and chiefly for combustion chambers burning slack coal; said roofs consist of 10 hard refractory blocks which will withstand a high heat and are made in a special shape,

said blocks being suspended from a su1table metallic structure.

A suspended roof according to the invention consists-essentially of a metallic structure to which are secured suitable section iron members-preferably I-irons-by their upper flanges, said members being in parallel position, with the proper spacing; the lower flanges of said members serve for the suspension of the refractory blocks which are so constructed as to be hung from the said flanges with a suflicient play to render them loosely slidable thereupon. Another special feature-of the invention consists in attaching the suspension beams to the ,main structure, not in a direct and permanent manner, but through the intermediary of hangers whose shape is such that the upper flange 0 of the suspension beam, which is laid the hanger, may be freely slidable therein, so that the suspension beams will be allowed a free movement of expansion. I On the other hand, the suspension beams are formed 1n sections, of 1.00-1.20 m. length; and are disposed in said hangers at suitable distances.

apart, so as to reduce the vertical deflection of the said beams due to the diiferences 1n 7 expansion caused by differences ln'temperature between their u per and lower flanges. I Anotherfeature o the invention relates to v the shape of the refractory blocks, thlsbemg such that any two adjacent blocks, in the lengthwise as well as in the transverse direction, will have between them a certain play which increases from the top part near the suspension members to the bottom part forming the surface of the arch; th1s provldes for expansion depending upon the temperature. For the joints between the ad acent blocks, the latter are preferably glven a su table shape to provide for the I overlapping of the sald bloc s 1n a given row, i. e. in the transverse" direction and perpendicular to the axis of the suspens on beams, each lateral face of the block having therein roper fitting ora suitable channel or groove, parallel to the axis of said beams, wherein is inserted a rod of baked refractory material which thus occupies the oppositely situated channels of any two adjacent rows of blocks.

According to the said invention I further provideflat the ends of the said suspension beams, suitable end blocks which are properly suspended, the shape .of said blocks being such as to ensure in a constant manner the oint whichis formed on the one hand with the rearwardly' situated blocks and on the other hand with the front wall of the furnace, irrespectively of all movements caused by differences in expansion.

The appended drawings show by way of example an embodiment of the invention.

In'Figs. 1 to 7 the arrangement relates to an inclined roof or .crown of a furnace for a multitubular boiler, disposed between'the front wall of the furnace F and the lower cylindrical recipient B of the boiler. Fig. 1 is a longitudinal section, i. e. parallel to the suspension members and from front to rear of the furnace. Fig. 2 is avertical cross-section on the line II-II of Fig. 1. Figs. 3 and 4; are respectively a side view on a larger scale of the hanger for the suspension beams, and a section of said hanger on the line IVIV Fig. 3. Fig. 5 shows a detail on a larger scale and in section on the line V-V, Fig. 1, illustrating the manner in which the suspension beams are supported at the rear end. Figs. 6 and 7 are views on a larger scale showing the iefractory blocks, said views being respectively asection perpendicular to the suspension members and a side view of one of the blocks. Figs. 8, 9 and 10 relateto a modification, employed for furnace roofsfor Babcock boilers, with mechanical stoking, and illustrate an arrangement ofrefractory blocks at the end of the series, providing for the joint between the precedin'g blocks and the front wall of the furnace. Fig. 8 shows at a larger scale a detail of the connection of the furnace arch to the boiler. Fig. 9 is a section on line II-II of Fi 8, and

' .Fig. 10 is a section on line III-III 0 Fig. 9.

In Figs. 1 to 7, the structural frame, supported by the lateral uprights of the boiler, consists of transverse girders one of which,

. 1, of a very constructionand comprising various section 11011 members riveted toether, is mounted along the front wall of the mace; the other girders 1', 1", consisting of strong section iron members, are disposed in variable number according to the length of the furnace roof, and are secured together by the longitudinal girders 2.

The transverse girders comprise suitable means for attaching the longitudinal I-irons from which the fire brick pieces are suspend ed. As concerns the front girder 1, the sus-' pension members S are simply riveted or bolted thereto at 3; as to the other transverse girders, the suspension members must be mounted so that they may slide freely under the eflects of expansion; to this end the beams 1 have riveted at 5 below their lower flange the hangers 4' made of cast steel and having a special form for the insertion of the upper flange of the said suspension members S. Since the beam 1" is in the inclined position and is perpendicular to the suspension membars, the latter may be mounted thereon in a simple manner by the use of an iron member 4" withcurved ends which is riveted to the beam. 1", Fig. 5.

In this manner the said suspension members which are divided into various sections of 1 to 12 metre length are loosely suspended from the main structure. The first members S, at their forward ends which withstand the entire thrust due to the inclination of the roof, are riveted or bolted at 3 as observed, and the ends of the said members, as well as those of the succeeding members, are simply inserted into the ban ers 4' or suspended from the flat iron mem r 4". In this manner the members S S S" which are situated in alignment will come into contact with each other at the ends, while at the same time they are enabled to slide in their supports in order to provide for the longitudinal expansion, and to assume their natural deflection due to the difference of temperature between the flanges, without causing stresses upon their supports. The juxtaposed ends of the said members are cut at a slight angle, Fi n 1, so that the space will increase towards the bottom.

The distance between centres of the members S corresponds to the transversal dimension of a fire-brickpieoe, to which is added the requisite play for the expansion of the said piece.

The blocks of fire-brick R, Figs. 6 and 7 are givena suitable shape whereby they may be fitted by their lateral grooves upon the members S; the said blocks are mounted by sliding them into place from the rear part of the roof, before the mountin of the plates 6 cov ering the recipient B, T e joints between the said blocks in the transverse direction have the form shown at 7 The grooves 8 of semicircular section are formed in the lateral faces of the-blocks, and a corresponding fire brick .member 9 is inserted into the two opposite grooves; it-being coextensive with the series of blocks in each case. The wall of the blocks which .will expand the most; on the-other hand, it is important that the lower edges of the several blocks which are more fragile since they are exposed to the greatest heat, shall not come into contact with each other .and shall not be obliged to support the effects being formed by the member 9.

Expansion can thus take place freely in the transverse direction between two rows of blocks as well as in the len thwise direction from front to rear, the memfioers S sliding in their hangers and the blocks R upon the mem bers S. The rear end 10 of the roof is en-' tirely free; it supports the lower edge of the plates protecting the cylindrical recipient which follows the movement of expansion, the same being simply secured at 11 to the members S and bearing at the other end upon the boiler tubes 12.

The top' of the roof or arch is not tobe covered with any layer of a refractory or insulating nature, and the roofis constructed to withstand very high temperatures; the joints which are constituted on the above-mentioned principle will be quite suflicient; the slight admission of cold air which may take place by reason of the draught has the advantage of coolin the framing and the said blocks, which 0 ers a great advantage as regards their duration; this small admission of air' will offer no inconvenience, since it takes place in the combustion chamber itself in which the proportions of fuel and comburant can be regulated in consequence.

Obviously, the said arrangement is given solely by way of example; the construction of the framing must evidently be adapted for each particular use; the shape of the refractory blocks and the'form of their attachmg .means may be'varied within wide limits-without departing from the spirit of the invention. .Figs. 8 to 10 illustrate a modification adapted for a furnace roof for a Babcock boiler"withmechanically'oper-ated grate, and

is the front wall situated below thetubes 12! and resting for examplev upon a set of fire brick blocks 13 mounted upon a frame 14 and forming at the front part a wall with a plane and rectilinear face. In this case the furnace exposed to the action of the fire is the one roof is terminated by the end blocks 15 which have .the s ecial form shown in Figs. 8 and 9; at each si e is a cut-out portion 16 co-operating with theflange 17 of the suspension member S; the inner end 16 of the said cut-out portion co-operateswith a suitable end portion 18, serving to attach the same to the upwardly curved end of the flange 17. At the lower part,.the block comes into contact with the last block R, of the regular roof series. In this manner,, according to the differences in the expansion of the member S and the set of blocks R, the end block 15 may pivot on its point of suspension 19. The

joint between adjacent blocks is obtained by means of the fire brick bars 20in the same manner as shown in Fig. 3 for the roof blocks,

' allowing a suflicient play to prevent all efforts between the blocks and the fire brick cylinders, whatever may be the movement of .the blocks.

The joint between the said portion and the front wall should provide for the movements of the end of the roof without bringing any efforts upon the fire brick parts which are fragile when heated. For this purpose, the

joint between the end blocks 15 and the blocks of the front wall 13 are formed by a set of fire brick cylinders 21, adjusted for an exact fit, which are adapted to roll by their own weight into the angle of the joint; to this may be added a refractory joint-filling sub-- stance in the stateof dry powder. Obviously, when in the cold state a suflicient play must be allowed between the blocks 13 and 15 which shall prevent all contact between the said blocks.

The general arrangement as set forth will provide for the easy and rapid upkeep of the roof or crown. v The parts which are the most exposed and the most subject to wear are the end blocks 15; but as they are simply hung from their points of suspension 19 and as the sections. of thejoint cylinders 21 are free to move, the said blocks can be replaced in a few minutes.

Claims:

' 1. A. roof for furnaces having a metal framework, a plurality of supports carried thereby and arranged in longitudinal alignment inclined from front to rear of the furnace, the said framework comprising transverse members to which the supports are secured, a plurality of successive sections of aligned beams having flanges adapted to engage said supports, the ends of two consecutlve sections of said beams resting in contiguity in a common intermediate support and bearing against each other at their upper part, the ends of said beams being cut on a bevel permitting a play between them towards the bottom, said beams being provided with lower flanges and refractory blocks suspended from said lower flanges between successive rows thereof, the faces ofsaid blocks being bevelled to permit increasing play toward-their lower ends.

2. In a roof for furnaces, a metal framework, a plurality of supports suspended therefrom, successive aligned sections of flanged beams carried by said supports, a plurality of refractory blocks suspended from said beams, and pivoted end blocks loosely suspended from the ends of said beams, whereby said end blocks may ivot upon their point of suspension in accor ance with expansion and contraction of the beams and adjacent blocks, said end blocks bearin at one face upon the last refractory block 0 the roof with the joint between the end block and the fixed wall of the furnace being formedby cylindrical sections of refractory material adapted to ,foll loosely in the angle of the joint between said walland block.

of beams may have free access of air, said blocks having their front and rear faces .bevelled, whereby said blocks may move longitudinally with respect to each other understres, the amount of such play increasing toward the bottom of said blocks.

4; In a roof for furnaces, a metallic frame work, a pluralit of aligned supports secured thereto, a plura ity of sectional aligned members freely engaging in said supports,.blocks 7 carried by saidmembers and end blocks bear-' ing on said blocks and pivoted to said-members, the said sectional members being bevelled to allow of free independent bendingthereof and said blocks being bevelled so that play between them shall increase toward their lower ends, the said end blocks being adapted to turn on their pivots under stresses produced bysaid beams or blocks, and

the joint betweeh the end block and the fixed wall of the furnace being formed by cylindrical sections of refractory material adapted to roll loosely in the angle of the joint between such wall and the pivoted end block. In testimony whereof I have hereunto set my hand. 0 E DU 

